The present invention relates generally to an elevator safety apparatus and, in particular, to an apparatus for actuating an elevator safety mechanism in response to excessive car speed.
A device for actuating a safety catch used in an elevator system is shown in the French patent specification no. 794 510 in which a lever linkage on the car triggers a safety catch when a control cable of a speed regulator breaks, when one or more car suspension cables extend or break, or when the elevator car is moving at an excessive speed during downward travel.
A device for actuating two safety catches, which are each arranged separately from the other, of a elevator car at the same time is shown in the German patent specification no. 28 26 309 in which a shaft has a triggering lever at both ends each of which is connected with a respective one of the safety catches engaging guide rails. The triggering levers are adjustably connected with the shaft so that an absolutely equal setting for actuating both of the safety catches can be achieved in the case of deployment.
A further device for the actuating of a safety catch in an elevator system is shown in the Swiss patent specification no. 369 566 in which an endless control cable connected with a car drives a regulator controlling a catching device of the car. The control cable is anchored to the car by way of a triggering device. The triggering device also triggers the catching device in the case of breakage of the control cable and the elevator car is brought to standstill, whereby serious accidents are prevented in advance.
A disadvantage of these known devices for the actuation of safety equipment in an elevator system lies in that they actuate safety equipment which brings the elevator car to a standstill only in the downward direction of travel when a car speed exceeds the normal speed by a certain amount, when a regulator cable breaks or when one or more car suspension cables extend or break.